阅读说明：本技术 一种检测阿尔茨海默症标志物的电化学核酸适配体传感器、制备方法、测试方法、检测仪 (Electrochemical nucleic acid aptamer sensor for detecting Alzheimer disease marker, preparation method, test method and detector ) 是由 徐庆 刘一镳 刘琼 张学记 于 2020-11-02 设计创作，主要内容包括：本发明公开了一种检测阿尔茨海默症标志物的电化学核酸适配体传感器、制备方法、测试方法、检测仪。所述电化学核酸适配体传感器的制备方法,包括：将三水氯金酸溶液和六水氯铂酸溶液混合,得到混合液；以Ag/AgCl电极为参比电极,铂电极为辅助电极,玻碳电极为工作电极搭建沉积三电极体系,将所述沉积三电极体系置于所述混合溶液中通过电化学工作站进行电化学沉积,得到表面沉积金铂纳米结构的玻碳电极；在所述表面沉积金铂纳米结构的玻碳电极表面滴加核酸适配体进行孵育,制备得到所述电化学核酸适配体传感器。本发明所述电化学核酸适配体传感器具有高灵敏度、高特异性、成本低廉、检测速度快等优点。(The invention discloses an electrochemical nucleic acid aptamer sensor for detecting Alzheimer's disease markers, a preparation method, a test method and a detector. The preparation method of the electrochemical aptamer sensor comprises the following steps: mixing chloroauric acid trihydrate solution and chloroplatinic acid hexahydrate solution to obtain mixed solution; an Ag/AgCl electrode is used as a reference electrode, a platinum electrode is used as an auxiliary electrode, a glassy carbon electrode is used as a working electrode to build a deposition three-electrode system, the deposition three-electrode system is placed in the mixed solution to carry out electrochemical deposition through an electrochemical workstation, and the glassy carbon electrode with a gold-platinum nano structure deposited on the surface is obtained; and dripping aptamer on the surface of the glassy carbon electrode with the gold-platinum nano structure deposited on the surface for incubation to prepare the electrochemical aptamer sensor. The electrochemical nucleic acid aptamer sensor has the advantages of high sensitivity, high specificity, low cost, high detection speed and the like.)

1. A method for preparing an electrochemical aptamer sensor for detecting Alzheimer's disease markers, which comprises the following steps:

mixing chloroauric acid trihydrate solution and chloroplatinic acid hexahydrate solution to obtain mixed solution;

taking a glassy carbon electrode as a working electrode, building a deposition three-electrode system by using the working electrode, a reference electrode and an auxiliary electrode, and performing electrochemical deposition on the deposition three-electrode system in the mixed solution by using an electrochemical workstation to obtain the glassy carbon electrode with a gold-platinum nanostructure deposited on the surface;

and dropwise adding a nucleic acid aptamer on the glassy carbon electrode with the gold-platinum nanostructure deposited on the surface for incubation to prepare the electrochemical nucleic acid aptamer sensor.

2. The method for preparing an electrochemical aptamer sensor for detecting Alzheimer's disease markers, according to claim 1, wherein the glassy carbon electrode is a pretreated glassy carbon electrode;

the pretreated glassy carbon electrode is prepared by the following steps:

grinding the glassy carbon electrode by adopting polishing flannelette, wherein alumina powder is distributed on the polishing flannelette;

and (2) taking a glassy carbon electrode as a working electrode, building a cleaning three-electrode system by using the working electrode, a reference electrode and an auxiliary electrode, placing the cleaning three-electrode system in a sulfuric acid solution, and cleaning the glassy carbon electrode by using an electrochemical workstation cyclic voltammetry to obtain the pretreated glassy carbon electrode.

3. The method for preparing an electrochemical aptamer sensor for detecting Alzheimer's disease markers, according to claim 1, wherein the concentration of the chloroauric acid trihydrate solution is 10mmol/L, and the concentration of the chloroplatinic acid hexahydrate solution is 10 mmol/L.

4. The method for preparing an electrochemical aptamer sensor for detecting Alzheimer's disease markers according to claim 1, wherein the sequence of the aptamer is as follows:

CAGCACCGTCAACTGAATGGGTTGGCCGGGCAGCGGGGGGTAGGCTTGGTGATGCGATGGAGATGT。

5. the method for preparing an electrochemical aptamer sensor for detecting Alzheimer's disease markers, according to claim 1, wherein in the electrochemical deposition process, an electrochemical workstation adopts a time-current program, and the voltage is set to-0.2V to-0.6V.

6. The method for preparing an electrochemical aptamer sensor for detecting Alzheimer's disease markers, according to claim 1, wherein the reference electrode is an Ag/AgCl electrode, and the auxiliary electrode is a platinum electrode.

7. An electrochemical aptamer sensor for detecting a marker for alzheimer's disease, comprising: the metal-platinum nano-structure comprises a glassy carbon electrode, a gold-platinum nano-structure layer coated on the glassy carbon electrode, and an aptamer combined on the gold-platinum nano-structure layer.

8. A current response test method for an electrochemical aptamer sensor for detecting markers for alzheimer's disease, comprising:

dripping a disease marker solution on the electrochemical aptamer sensor as claimed in claim 7 to obtain an electrochemical aptamer sensor for capturing a disease marker;

and (3) using an electrochemical workstation, taking the electrochemical aptamer sensor for capturing the disease marker as a working electrode, building a test three-electrode system by using the working electrode, a reference electrode and an auxiliary electrode, and detecting a current response value in a ferrocene methanol solution by using a differential pulse method.

9. The method for testing the current response of an electrochemical aptamer sensor for detecting markers of Alzheimer's disease according to claim 8, wherein the disease marker solution is a T-tau protein solution.

10. A test device for detecting Alzheimer's disease markers, comprising the electrochemical aptamer sensor for detecting Alzheimer's disease markers according to claim 7.

Technical Field

The invention relates to the technical field of sensing, in particular to an electrochemical aptamer sensor for detecting Alzheimer's disease markers, a preparation method, a test method and a detector.

Background

At present, a plurality of methods for detecting the Alzheimer's disease biomarkers, such as radioimmunoassay, electrochemiluminescence, colorimetry and the like, are available, but most of the detection methods are complicated, complex to operate, expensive in equipment and cost and high in detection limit, so that the establishment of a rapid, simple and sensitive detection method is of great significance.

Accordingly, the prior art is yet to be improved and developed.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention aims to provide an electrochemical aptamer sensor for detecting alzheimer's disease markers, a preparation method, a test method, and a detector, and aims to solve the problem of high detection limit of the existing alzheimer's disease biomarker detection sensors.

A method for preparing an electrochemical aptamer sensor for detecting Alzheimer's disease markers comprises the following steps:

mixing chloroauric acid trihydrate solution and chloroplatinic acid hexahydrate solution to obtain mixed solution;

taking a glassy carbon electrode as a working electrode, building a deposition three-electrode system by using the working electrode, a reference electrode and an auxiliary electrode, and performing electrochemical deposition on the deposition three-electrode system in the mixed solution by using an electrochemical workstation to obtain the glassy carbon electrode with a gold-platinum nanostructure deposited on the surface;

and dropwise adding a nucleic acid aptamer on the glassy carbon electrode with the gold-platinum nanostructure deposited on the surface for incubation to prepare the electrochemical nucleic acid aptamer sensor.

The preparation method of the electrochemical aptamer sensor for detecting the Alzheimer's disease marker comprises the following steps of (1) preparing a glassy carbon electrode, wherein the glassy carbon electrode is a pretreated glassy carbon electrode;

the pretreated glassy carbon electrode is prepared by the following steps:

grinding the glassy carbon electrode by adopting polishing flannelette, wherein alumina powder is distributed on the polishing flannelette;

and (2) taking a glassy carbon electrode as a working electrode, building a cleaning three-electrode system by using the working electrode, a reference electrode and an auxiliary electrode, placing the cleaning three-electrode system in a sulfuric acid solution, and cleaning the glassy carbon electrode by using an electrochemical workstation cyclic voltammetry to obtain the pretreated glassy carbon electrode.

The preparation method of the electrochemical aptamer sensor for detecting the Alzheimer's disease marker comprises the steps of preparing a chloroauric acid trihydrate solution, wherein the concentration of the chloroauric acid trihydrate solution is 10mmol/L, and the concentration of the chloroplatinic acid hexahydrate solution is 10 mmol/L.

The preparation method of the electrochemical aptamer sensor for detecting the Alzheimer's disease marker comprises the following steps:

CAGCACCGTCAACTGAATGGGTTGGCCGGGCAGCGGGGGGTAGGCTTGGTGATGCGATGGAGATGT。

the preparation method of the electrochemical aptamer sensor for detecting the Alzheimer's disease marker comprises the following steps that in the electrochemical deposition process, an electrochemical workstation adopts a time-current program, and the voltage is set to be-0.2V-0.6V.

The preparation method of the electrochemical nucleic acid aptamer sensor for detecting the Alzheimer's disease marker comprises the steps of preparing a reference electrode, preparing an auxiliary electrode, and carrying out electrochemical detection on the reference electrode and the auxiliary electrode.

An electrochemical aptamer sensor for detecting markers of alzheimer's disease, comprising: the metal-platinum nano-structure comprises a glassy carbon electrode, a gold-platinum nano-structure layer coated on the glassy carbon electrode, and an aptamer combined on the gold-platinum nano-structure layer.

A current response test method for an electrochemical aptamer sensor for detecting markers for alzheimer's disease, comprising:

dripping a disease marker solution on the electrochemical aptamer sensor to obtain the electrochemical aptamer sensor for capturing the disease marker;

and (3) using an electrochemical workstation, taking the electrochemical aptamer sensor for capturing the disease marker as a working electrode, building a test three-electrode system by using the working electrode, a reference electrode and an auxiliary electrode, and detecting a current response value in a ferrocene methanol solution by using a differential pulse method.

The current response test method of the electrochemical aptamer sensor for detecting the Alzheimer disease marker, wherein the disease marker solution is T-tau protein solution.

A detector for detecting an Alzheimer's disease marker, comprising the electrochemical aptamer sensor for detecting an Alzheimer's disease marker as described above.

Has the advantages that: the electrochemical aptamer sensor is a detection device for determining the concentration of a marker based on the strength of an electric signal, combines the advantages of a high-specificity immunoassay technology and an electrochemical analysis technology with high sensitivity and short reaction time, and has the advantages of high sensitivity, high specificity, easiness in modification and functionalization, low cost, high detection speed and the like.

Drawings

FIG. 1 is a scanning electron microscope image of the Au/Pt nano structure prepared by the present invention.

FIG. 2 is a graph showing analysis of detection performance of an electrochemical aptamer sensor prepared according to an example of the present invention.

Detailed Description

The invention provides an electrochemical aptamer sensor for detecting Alzheimer's disease markers, a preparation method, a test method and a detector, and the invention is further detailed below in order to make the purpose, technical scheme and effect of the invention clearer and clearer. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention provides a preparation method of an electrochemical aptamer sensor for detecting Alzheimer's disease markers, which comprises the following steps:

s100, mixing a chloroauric acid trihydrate solution and a chloroplatinic acid hexahydrate solution to obtain a mixed solution;

s200, building a deposition three-electrode system by using a glassy carbon electrode as a working electrode, a reference electrode and an auxiliary electrode, and performing electrochemical deposition on the deposition three-electrode system in the mixed solution by using an electrochemical workstation to obtain the glassy carbon electrode with a surface deposited gold-platinum nano structure;

s300, dripping aptamer on the glassy carbon electrode with the gold-platinum nano structure deposited on the surface for incubation, and preparing the electrochemical aptamer sensor.

The electrochemical nucleic acid aptamer sensor constructed by the invention is a detection device for determining the concentration of a marker based on the strength of an electric signal, and has the following advantages: firstly, the surface of the electrode is modified by adopting a gold-platinum nano structure, so that nonspecific adsorption in the detection process is reduced; secondly, the target substance is captured by using the nucleic acid aptamer which is low in price and easy to synthesize, and the cost is reduced.

(1) The gold-platinum nano structure prepared by the invention greatly increases the specific surface area of the substrate material, keeps strong electron transmission capacity, has good biocompatibility, can be effectively combined with a nucleic acid aptamer, and realizes the immobilization of the capture aptamer; moreover, the gold platinum nano structure with large surface area can reduce nonspecific adsorption, and has important significance for improving the sensitivity of the sensor.

(2) The detection aptamer does not need a label, the resistance of the electrode can be directly changed by the change of the concentration of the target object, and the change can be directly reflected by the current.

(3) The detection range of the electrochemical aptamer sensor prepared by the invention on the Alzheimer's disease marker t-tau is 0.1pg/mL-100 ng/mL.

S100 is to prepare a mixed solution for electrochemical deposition in S200, wherein the mixed solution contains gold ions and platinum ions. In one embodiment of the invention, the concentration of the chloroauric acid trihydrate solution is 10mmol/L, and the concentration of the chloroplatinic acid hexahydrate solution is 10mmol/L, so that a stable mixed solution can be obtained, and the gold-platinum nano structure can be obtained by deposition.

In the embodiment of the invention, before the glassy carbon electrode is used as a working electrode for electrochemical deposition, impurities on the surface of the electrode are removed, so that a clean and smooth electrode surface is obtained. That is, the glassy carbon electrode is a pretreated glassy carbon electrode.

In one embodiment of the invention, the glassy carbon electrode is a pretreated glassy carbon electrode;

the pretreated glassy carbon electrode is prepared by the following steps:

s201, grinding the glassy carbon electrode by using polishing flannelette, wherein alumina powder is distributed on the polishing flannelette;

s202, a washing three-electrode system is built by taking the glassy carbon electrode as a working electrode, a reference electrode and an auxiliary electrode, the washing three-electrode system is placed in a sulfuric acid solution, and the glassy carbon electrode is washed by a cyclic voltammetry method of an electrochemical workstation to obtain the pretreated glassy carbon electrode.

The S201 specifically includes: scattering proper amounts of 0.3micron (0.3 mu m) and 0.05micron aluminum oxide powder on the polishing flannelette, and adding proper amounts of water to respectively obtain the polishing flannelette scattered with 0.3micron aluminum oxide powder and the polishing flannelette scattered with 0.05micron aluminum oxide powder;

the glassy carbon electrode was ground (rubbed) on a polishing cloth sprinkled with 0.3micron alumina powder, followed by grinding with 0.05micron alumina powder, washing with an ultrasonic cleaner for 5min, and ultrasonic cleaning for 2 times.

The S202 specifically includes: cleaning with electrochemical workstation, using Ag/AgCl electrode as reference electrode, platinum wire electrode as auxiliary electrode, glassy carbon electrode as working electrode, and placing the three-electrode system in 0.5mmol/L H₂SO₄And cleaning the electrode by using cyclic voltammetry of an electrochemical workstation at a voltage of 0-1.6V until scanning curves are almost overlapped.

In the step S201, firstly, the impurities on the surface of the electrode are removed through rough polishing of alumina powder with the particle size of 0.3 mu m; and then grinding the glassy carbon electrode by using 0.05 mu m aluminum oxide powder with smaller particles, and finely polishing to remove impurities and simultaneously enable the surface of the electrode to be flat and smooth.

In S202, possible impurities remaining during the above operation in S201 are removed, and it is checked whether the electrode has been polished.

In S200, an electrochemical workstation is used, a glassy carbon electrode is used as a working electrode, a reference electrode and an auxiliary electrode to build a deposition three-electrode system, the three-electrode system is placed in an Au Pt mixed solution for deposition, and an AuPt nanostructure is deposited on the surface of the glassy carbon electrode, so that the glassy carbon electrode with a gold platinum nanostructure deposited on the surface is obtained.

As shown in fig. 1, the gold platinum nanostructure is a mixed metal nanostructure, which can reduce the adsorption of non-specific substances during biomarker measurement while maintaining the biocompatibility of the sensor.

In one embodiment of the present invention, during the electrochemical deposition process, the voltage of the electrochemical workstation is set to-0.2V to-0.6V, the deposition time is: 300s to 600 s. The parameters can ensure that the nonspecific adsorption resistance of the mixed metal nano structure formed on the surface of the glassy carbon electrode is better.

The S300 is binding of nucleic acid aptamers on a gold platinum nanostructure. The electrochemical aptamer sensor can be obtained by dripping aptamer solution on a glassy carbon electrode with a gold-platinum nanostructure deposited on the surface and incubating for 1h at 37 ℃.

Specifically, the S300 includes:

s301, rinsing the glassy carbon electrode with the deposited nano structure with ultrapure water, using the rinsed glassy carbon electrode as a working electrode to build a three-electrode system, placing the three-electrode system in an electrochemical workstation, scanning three cycles in 5mmol/L potassium ferricyanide within a voltage range of-0.2V-0.6V by adopting a Cyclic Voltammetry (CV), rinsing the working electrode with ultrapure water, and airing;

s302, dripping 20 mu L of aptamer on the surface of the electrode, and incubating for 1h at 37 ℃;

s303, washing the glassy carbon electrode combined with the nucleic acid aptamer with Phosphate Buffered Saline (PBS) and then using the washed glassy carbon electrode as a working electrode to build a three-electrode system, placing the three-electrode system in an electrochemical workstation, scanning for three cycles in 5mmol/Lol potassium ferricyanide by Cyclic Voltammetry (CV) within a voltage range of-0.2V-0.6V, washing with pure water, and airing.

Wherein the potassium ferricyanide solution is used to generate an oxidation current and a reduction current within a certain voltage range.

In one embodiment of the present invention, the sequence of the aptamer is: CAGCACCGTCAACTGAATGGGTTGGCCGGGCAGCGGGGGGTAGGCTTGGTGATGCGATGGAGATGT are provided.

The aptamers described in the embodiments of the present invention are different from conventional aptamers. The aptamer fixes DNA on the surface of a gold-platinum nano structure through self-assembly of-SH, and the high biological affinity of the nano structure is favorable for forming Au-S bonds.

Specifically, the reaction that occurs during the formation of the Au — S bond:

R-SH+Au→R-S·-Au+e^-+H⁺

it can be seen that the formation process of the Au-S bond realizes the immobilization of the aptamer on the surface of the glassy carbon electrode.

The nucleic acid aptamer is combined with a gold-platinum nano structure on the surface of an electrode through a gold-sulfur bond, so that the aptamer is fixed on the surface of the electrode. In one embodiment of the invention, the incubation temperature is 37 ℃.

In one embodiment of the invention, the reference electrode is an Ag/AgCl electrode (silver/silver chloride electrode) and the auxiliary electrode is a platinum electrode. The silver/silver chloride electrode has the characteristics of high precision and durability. The auxiliary electrode and the research electrode form a polarization loop to enable the research electrode to have current to pass through. The platinum electrode itself has a small resistance and is not easily polarized.

The invention also provides an electrochemical aptamer sensor for detecting the Alzheimer's disease marker, which comprises the following components: the metal-platinum nano-structure comprises a glassy carbon electrode, a gold-platinum nano-structure layer coated on the glassy carbon electrode, and an aptamer combined on the gold-platinum nano-structure layer.

The electrochemical aptamer sensor can be prepared by the preparation method of the electrochemical aptamer sensor. In the electrochemical nucleic acid aptamer sensor, the nucleic acid aptamer is combined with a gold-platinum nanostructure on the surface of an electrode through a gold-sulfur bond, so that the aptamer is fixed on the surface of a glassy carbon electrode.

The invention provides a current response test method of an electrochemical aptamer sensor for detecting Alzheimer's disease markers, which comprises the following steps:

s400, dripping a disease marker solution on the electrochemical aptamer sensor to obtain the electrochemical aptamer sensor for capturing the disease marker;

s500, using an electrochemical workstation, building a test three-electrode system by using the electrochemical aptamer sensor for capturing the disease markers as a working electrode, a reference electrode and an auxiliary electrode, and detecting a current response value in a ferrocene methanol solution by using a differential pulse method.

The current response test method can be used for obtaining the current response value of the electrochemical aptamer sensor, detecting a standard curve and calibrating the electrochemical aptamer sensor.

In S400, specifically, a disease marker protein is dripped on the surface of the electrochemical aptamer sensor, and the electrochemical aptamer sensor is kept still (incubated) for 1h to enable the protein to be captured by the aptamer.

In one embodiment of the invention, the disease marker solution is a T-tau protein solution.

In S500, the sensor capturing the disease marker protein can express the concentration of the disease marker protein through the current signal, thereby achieving the purpose of detecting the concentration of the disease marker. Wherein, the reference electrode is Ag/AgCl, and the auxiliary electrode is a platinum wire electrode.

In one embodiment of the invention, the concentration of the ferrocene methanol solution is 1 mmol/L.

In one embodiment of the invention, in the process of detecting the current response value by using the differential pulse method, the initial voltage is set to be 0V by the parameter, and the final voltage is set to be 0.4V.

The invention provides a detector for detecting Alzheimer's disease markers, which comprises the electrochemical aptamer sensor for detecting the Alzheimer's disease markers.

Specifically, the detector for detecting the Alzheimer's disease marker comprises: the electrochemical working station comprises a ferrocene methanol solution, a three-electrode system positioned in the ferrocene methanol solution and an electrochemical working station connected with the three-electrode system; wherein the three-electrode system comprises a reference electrode, an auxiliary electrode and an electrochemical nucleic acid aptamer sensor as a working electrode.

The electrochemical aptamer sensor constructed by the invention is a detection device for determining the concentration of a marker based on the strength of an electric signal, combines the advantages of a high-specificity immunoassay technology and an electrochemical analysis technology with high sensitivity and short reaction time, and has the advantages of high sensitivity, high specificity, easiness in modification and functionalization, low cost, high detection speed and the like. Therefore, the electrochemical nucleic acid aptamer sensor has important application value in the fields of chemistry, biomedicine, food safety and the like.

The technical solution of the present invention will be described below by specific examples.

Example 1

1. Mixing 10mmol/L chloroauric acid trihydrate solution and 10mmol/L chloroplatinic acid hexahydrate solution according to a certain proportion to form a mixed solution of gold and platinum for later use;

2. pretreating a glassy carbon electrode:

the method comprises the steps of scattering a proper amount of 0.3micron aluminum oxide powder on polishing flannelette, adding a proper amount of water, placing a glassy carbon electrode on the aluminum oxide scattered with 0.3micron for grinding, then grinding on the polishing flannelette scattered with 0.05micron aluminum oxide, cleaning for 5min by using an ultrasonic cleaner, and cleaning for 2 times.

Cleaning with electrochemical workstation, using Ag/AgCl electrode as reference electrode, platinum wire electrode as auxiliary electrode, glassy carbon electrode as working electrode, and placing the three-electrode system in 0.5mmol/L H₂SO₄And cleaning the electrode by using cyclic voltammetry of an electrochemical workstation at 0-1.6V until scanning curves are almost overlapped.

3. Preparing a nano structure: and (3) using an electrochemical workstation, adopting a three-electrode system, taking an Ag/AgCl electrode as a reference electrode, taking a platinum wire electrode as an auxiliary electrode, taking a treated glassy carbon electrode as a working electrode, placing the three-electrode system in an Au Pt mixed solution, and adopting a time-current program in the electrochemical workstation to deposit a gold platinum nanostructure on the surface of the glassy carbon electrode. Wherein the parameters of the deposition process are set as follows: voltage: -0.2V to-0.6V; deposition time: and (4) 400 s.

4. Preparation of electrochemical aptamer sensor: washing the glassy carbon electrode with the deposited nano structure with ultrapure water, placing the glassy carbon electrode in an electrochemical workstation, building a three-electrode system by adopting a Cyclic Voltammetry (CV), placing the three-electrode system in 5mmol/L potassium ferricyanide, scanning for three cycles within a voltage range of-0.2V-0.6V, washing the working electrode with ultrapure water, and airing. Dripping 20 mu L of aptamer on the surface of an electrode, incubating for 1h at 37 ℃, washing with PBS, then building a three-electrode system, placing the three-electrode system in an electrochemical workstation, building the three-electrode system, placing the three-electrode system in 5mmol/L potassium ferricyanide, scanning for three cycles within the voltage range of-0.2V-0.6V, washing with pure water, and airing to finish the modification of the aptamer.

5. Dripping 10 mu L of 0.1-100000 pg/mL (such as 400pg/mL) of disease marker T-tau protein solution, incubating for 1h at 37 ℃, washing the surface of an electrode by PBS, and drying in the air to prepare the electrochemical nucleic acid aptamer sensor for detecting the Alzheimer's disease marker.

6. And (3) detection:

an electrochemical workstation is used for testing by a three-electrode system, an Ag/AgCl electrode is used as a reference electrode, a platinum wire electrode is used as an auxiliary electrode, the prepared sensor is used as a working electrode, and a differential pulse method (DPV) is used for detecting a current response value in a ferrocene methanol solution with the volume of 20mL and the volume of 1 mmol/L; the initial voltage was set to 0V and the final voltage to 0.4V by the parameters.

FIG. 2 is a graph (standard curve) showing the analysis of the detection performance of the electrochemical aptamer sensor prepared according to the example of the present invention. The electrochemical aptamer sensor has the characteristics of high sensitivity and high specificity, and can be used for detecting the Alzheimer's disease biomarker.

It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.